Hahahaha I actually spell it HELLsinki too usually, I wish I could have given you the heads up, I was actually there the same time you were! Helsinki is a nice city if you know what to do and where to go. You surely had quite the trip, but at least you got to go to sauna and dip into the icy sea, nothing more Finnish than that.

I don’t think you can fly a drone anywhere without a permit these days, especially in the cities. They did change the laws quite recently so no wonder you didn’t know about it.